A team of the University of Bucharest placed first in the Competition Unbreakable Romania (season spring-summer 2021). Congratulations to Dragos Albastroiu, Mihail Feraru (undergraduates at Faculty of Mathematics and Computer Science), and Andrei Ciobanu (master student enrolled at our Security and Applied Logic master program) for finishing the team competition on the first place! More information available here.
The University of Bucharest is placed in the top for the best score at the Individual Competition Unbreakable Romania (season spring-summer 2021). Congratulations to Dragos Albastroiu, undergraduate at Faculty of Mathematics and Computer Science, for finishing the individual competition on the first place! More information available here.
Title: Active Defense in Cybersecurity
Speaker: Sergiu Bogdan Meseșan & Andreea Drugă, Cybersecurity Specialists at ENEA
- Active Defense Mechanisms – Notions, principles and Active Defense mechanisms (ca.1h)
- Practical Application for Honeypot Analytics and Attacks Data Collection – Presentation of a platform implemented by ENEA specially for this lecture, a practical demo of Active Defense (ca.1h)
- Active Defense DIY – Workshop installation, running, Internet access for a Honeypot type VM using an open source platform (Telekom Tpot CE) (ca.1h-1.5h)
For the students interested to attend the meeting: please contact Ruxandra Olimid (email@example.com)
Title: Kernelization, Proof Complexity and Social Choice
Speaker: Gabriel Istrate (West University of Timișoara)
We display an application of the notions of kernelization and data reduction from parameterized complexity to proof complexity: Specifically, we show that the existence of data reduction rules for a parameterized problem having (a) a small-length reduction chain, and (b) small-size (extended) Frege proofs certifying the soundness of reduction steps implies the existence of subexponential size (extended) Frege proofs for propositional formalizations of the given problem. We apply our result to infer the existence of subexponential Frege and extended Frege proofs for a variety of problems. Improving earlier results of Aisenberg et al. (ICALP 2015), we show that propositional formulas expressing (a stronger form of) the Kneser-Lovasz Theorem have polynomial size Frege proofs for each constant value of the parameter k. Previously only quasipolynomial bounds were known (and only for the ordinary Kneser-Lovasz Theorem). Another notable application of our framework is to impossibility results in computational social choice: we show that, for any fixed number of agents, propositional translations of the Arrow and Gibbard-Satterthwaite impossibility theorems have subexponential size Frege proofs.
This is joint work with Cosmin Bonchiș and Adrian Crăciun.
Title: An Introduction to Protocols in Dynamic Epistemic Logic
Speaker: Alexandru Dragomir (University of Bucharest)
Title: Regular matching problems for infinite trees
Speaker: Mircea Marin (West University of Timișoara)
This is joint work with Carlos Camino, Volker Diekert, Besik Dundua and Géraud Sénizergues.
 C. Camino, V. Diekert, B. Dundua, M. Marin, G. Sénizergues, Regular matching problems for infinite trees. arXiv:2004.09926 [cs.FL], 2021.
Title: A proof mining case study on the unit interval
Speaker: Andrei Sipoș (University of Bucharest & IMAR)
Title: Exponential Diophantine equations over ℚ
Speaker: Mihai Prunescu (University of Bucharest & IMAR)
In a previous exposition  we have seen that the solvability over ℚ is undecidable for systems of exponential Diophantine equations. We now show that the solvability of individual exponential Diophantine equations is also undecidable, and that this happens as well for some narrower families of exponential Diophantine equations.
We are pleased to support UNbreakable Romania – the national competition organised for students in the country preparing for a career in cybersecurity.
- The preparation stage will start on April 1 when the registered participants will have at their disposal theoretical and practical resources that will allow them to become familiar with the format and methodology of the contest.
2. The individual contest will take place between May 14-16.
3. The team competition will take place on June 4-6.
At the end of the season, there will be a national #ROEduCyberSkills ranking that will provide an overview of cybersecurity performance in Romania.
Registration is free and is available on the official website: https://unbreakable.ro/inregistrare
Title: Unwinding of proofs
Speaker: Pedro Pinto (TU Darmstadt)
In this talk, we set out to give a brief introduction to the proof mining program, focusing on the following points:
- functional interpretations in an introductory way;
- the bounded functional interpretation [3,4];
- a concrete translation example: the metric projection argument.
We finish with a brief discussion of some recent results [5,6].
 U. Kohlenbach. Proof-theoretic methods in nonlinear analysis. In M. Viana B. Sirakov, P. Ney de Souza, editor, Proceedings of the International Congress of Mathematicians – Rio de Janeiro 2018, Vol. II: Invited lectures, pages 61–82. World Sci. Publ., Hackensack, NJ, 2019.
 F. Ferreira and P. Oliva. Bounded functional interpretation. Annals of Pure and Applied Logic, 135:73-112, 2005.
 F. Ferreira. Injecting uniformities into Peano arithmetic. Annals of Pure and Applied Logic, 157:122-129, 2009.
 B. Dinis and P. Pinto. Effective metastability for a method of alternating resolvents. arXiv:2101.12675 [math.FA], 2021.
 U. Kohlenbach and P. Pinto. Quantitative translations for viscosity approximation methods in hyperbolic spaces. arXiv:2102.03981 [math.FA], 2021.